NTP Orphan Mode

The NTP Orphan Mode allows NetClock to remain a valid time server to its NTP clients even if all its input references have become invalid and the Holdover period has expired.

Per default, NetClock will automatically downgrade itself to NTP Stratum 15, should its input references become invalid and after expiration of the Holdover period. By setting the NTP Orphan Mode to an NTP Stratum level other than 15, NetClock will continue to be considered a valid time server by its NTP clients.

Note, however, that the time served by NetClock after expiration of the Holdover period can be of a low quality and therefore normally ought to be considered invalid. NTP Orphan Mode exists as an option for timing networks that must stay intact even if the time distributed is invalid. The other use case for Orphan Mode is to allow for NTP to be utilized in an isolated timing network that is designed to normally operate without any external references.

To configure NTP Orphan Mode:

Navigate to MANAGEMENT > NTP Setup.

In the NTP Services panel, click the GEAR icon in the top right corner. The Edit NTP Services window will open:

Click the Orphan Mode tab, and select an NTP Stratum other than 15. This will be the Stratum level NetClock will transition to in the event its input references become invalid.